WO2011035949A2

WO2011035949A2 - Organic uncoupling agents

Info

Publication number: WO2011035949A2
Application number: PCT/EP2010/060792
Authority: WO
Inventors: Roland Jacquot; Luc Louvel; Philippe Marchal; Philippe Marion; Gilles Moreau; Agnes Pilas-Begue
Original assignee: Rhodia Operations
Priority date: 2009-09-22
Filing date: 2010-07-26
Publication date: 2011-03-31
Also published as: EP2480072A2; FR2950226B1; FR2950226A1; WO2011035949A3; CN102711457A; US20130005810A1; KR20120101349A; JP2013505277A

Abstract

The present invention relates to a method for controlling the growth of bacterial biomass in an aqueous system, including adding to the aqueous system or contacting the aqueous system with an efficient amount of an uncoupling agent selected from vanillin, pentaerythritol and a betaine of the general formula (1): (R)₃N⁺=(CH₂)n=CO₂ ^-, where the R groups are identical or different and are selected from a linear or branched alkyl group having 1 to 8 carbon atoms and n is a number between 1 and 5.

Description

ORGANIC DECOUPLING AGENTS

The invention relates to organic derivatives and their use as decoupling agents. The present invention relates to such decoupling agents for use in the regulation of bacterial biomass in aqueous systems, particularly in wastewater treatment plants, as well as the use of such agents and a process use of these agents.

The decoupling activity of a molecule consists in acting on the bacterial cellular energetics so as to reduce the biomass production of the wastewater while keeping the purifying activity of the bacterial cell by biological degradation of organic molecules. The details of biochemistry and

mechanisms involved in cell respiration are exposed, for example, in the publication "Biochemistry", ^3rd edition, author: Lubert Stryer, publisher: WH Freemen & Company, New York, USA, 1998 and also in the publication " General Microbiology ", ^3rd edition, authors Roger Y. Stanier, Michael Doudoroff and Edward A. Adelberg, publisher: Macmillan, 1971. The uncoupling activity of a molecule on bacterial growth is ultimately expressed by an overconsumption of oxygen induced by an imbalance of the bacterial energy.

This decoupling activity of a molecule is interesting for a treatment plant application, hereinafter abbreviated as STEP, in the case where it makes it possible to reduce the production of activated sludge significantly at the source.

The production of biomass and thus activated sludge in the treatment of wastewater originates from the consumption of nutrients in the wastewater. By a breathing process, nutrients are oxidized and this releases energy that can be used by microorganisms as part of cell division. However, the consumption of nutrients induces a proton flux at the level of the bacterial membrane by the phenomenon of oxidative phosphorylation; this flux will establish a proton gradient which itself rotates proton pumps that allow the synthesis of ATP (adenosine triphosphate) from ADP + P at the level of the ATP synthetase enzyme complex. ATP provides energy to the cell during cellular processes (including cell division).

If this release of energy could be avoided, it would lead to a decrease in biomass generation by inhibiting the production of energy. Decoupling is the inhibition of the formation of energy reserves in the form of ATP. A decoupling agent decreases the energy efficiency of carbon combustion while increasing the proportion of oxidized carbon to CO2. Decoupling results in lower biomass production and higher oxygen consumption.

The bacterial biomass produced during wastewater treatment is expensive to eliminate and therefore a decrease in biomass leads to a reduction in disposal costs.

An object of the present invention is to propose decoupling molecules whose efficiency is measured by a decrease in the production of biological sludge at source, that is to say in the aeration basins of urban wastewater treatment plants. at least 30%.

Another object of the present invention is to provide uncoupling molecules whose efficiency is substantially equivalent to or even greater than the reference molecule THPS (Tetrakis hydroxymethyl phosphonium) whose effectiveness in reducing the production of biological sludge has been shown in FIG. the patent application WO 2004/1 13236.

Another aim of the present invention is to propose decoupler molecules that are alternative to THPS, whose abiotic and biotic degradability is less rapid than that of THPS, without the said molecules being non-degradable, which would pose environmental problems.

Another object of the present invention is to provide decoupling molecules whose toxicological and ecotoxicological profile is satisfactory and in adequacy with their use in STEP. Indeed, these molecules must have a low impact on the environment and ultimately be biodegradable while having a biotic and abiotic degradation allowing them to have a satisfactory reactivity on the bacterial biomass.

These and other objects are achieved by the present invention which indeed relates to a method for regulating the growth of bacterial biomass in an aqueous system comprising adding to the aqueous system, or bringing into contact with the aqueous system, an effective amount of a decoupling agent selected from vanillin, pentaerythritol and a betaine of general formula (1):

(1)

in which :

The same or different R groups are chosen from a linear or branched alkyl group having 1 to 8 carbon atoms and n is a number between 1 and 5.

Preferably, R is a methyl group, n is 1 and the product of formula (1) is referred to in the literature as trimethylglycine, N-trimethylglycine, glycine betaine or glycine of formula (2):

(2)

The effective amount of decoupling agent added to the aqueous system can be up to 5000 mg / l, for example up to 3000 mg / l, such as up to 1000 mg / l. Preferably, the effective amount of decoupling agent added to the aqueous system is from 0.005 mg / l to 500 mg / l, for example from 0.01 mg / l to 300 mg / l, such as 0.05 mg / l. at 100 mg / l. More preferably, the effective amount of decoupling agent is from 0.1 to 10 mg / l, for example from 0.5 mg / l to 7.5 mg / l, such as from 1 to 5 mg / l.

The decoupling agent may be formulated with one or more of the following conventionally used chemicals in the treatment of wastewater:

a surfactant;

an antifoam agent;

a scaling inhibitor;

a corrosion inhibitor;

a biocide;

a flocculant;

an agent facilitating the separation of solids / water; and

a dispersant. Preferably, the aqueous system will be a wastewater treatment plant that is used for the treatment of industrial or municipal effluents. This facility recovers wastewater from industrial processes (eg paper production, the food industry, the chemical industry) and / or domestic and institutional buildings and similar facilities, using microorganisms in aerobic, anoxic processes (eg denitrification), to consume organic pollutants and to make water suitable for reuse or release into the environment.

The present invention therefore provides a method for regulating the growth of bacterial biomass in an aqueous system, which method comprises contacting an effective amount of a decoupling agent as defined above directly with the bacterial biomass. . To implement this method, it is recommended to contact in a limited time a maximum volume of activated sludge with the decoupling agent so as to obtain optimal efficiency thereof.

Thus, for biological laboratory tests in the laboratory, the direct contact of the decoupling agent in water with the bacterial biomass is referred to as "flash dosing" or "flash mixing" in the English language flashmixing.

On the other hand, the effective amount of decoupling agent can be from 0.1 to 1000 milligrams per gram of solids present in the sludge (expressed as dry matter) in the aqueous system, preferably from 0.5 to 750 mg / g, by from 1 to 500 mg / g, such as from 5 to 100 mg / g.

Contacting the bacterial biomass directly and rapidly (in other words with optimal mixing) with the decoupling agent has been found to lead to an improvement of the decoupling agent efficiency by the regulation of the biomass bacterial. It has been found that if the decoupling agent is simply added directly to a sludge-containing bioreactor then the effectiveness of the agent is substantially diminished since the decoupling agent is capable of interacting with the other materials present in the bioreactor and that the action of this decoupling agent is substantially reduced. The following examples illustrate the invention without limiting its scope.

Example 1

Demonstration of sludge reduction by an organic derivative in oxitop screening tests:

To evaluate the reduction of sludge production by a decoupling chemical agent in screening, Oxitop® bottle respirometry is used. Bacterial strains known and representative of the activated sludge (because isolated in aeration tanks) are inoculated in a culture medium in the presence of a certain concentration of the decoupling agent over a period of 7 days. The comparison of the respiration of inocula treated compared to controls (inocula untreated) can measure the overconsumption of oxygen, physiological signature of the decoupling effect on bacteria.

The method and apparatus used are those described in Example 3 of WO 2004/1 13236 cited as a reference.

The results obtained in screening test on the strain of bacteria Shinella granuli, are summarized in Table 1 below. They are expressed as percentage decoupling with respect to the control (not including a decoupling agent). THPS (tetrakis (hydromethyl) phosphonium sulfate) produced decoupling effects in oxitop® respirometry tests of 16 ± 8% for a nominal concentration of 3 ppm, the 95% confidence interval of THPS in terms of decoupling factor being [10-22], values calculated from the results obtained in 26 Oxitop® trials.

Table 1

Corn; entratior IS

0 1 0 5 20

1 ppm 2 ppm 3 ppm 8 ppm 10 ppm ppm ppm ppm

16% *

THPS

[10-22]

Vanillin 5% 18% 14% 18% -25% 15% -22% 21% -21% 18% -23% 18%

Pentaeryt 21-21% -

2% 8% 15- 17% - 17% 19% 22% hritol 19%

wistaria

5% 18% 0% 20% -26% 24% -25% 20% -26% 12-20% betaine The toxicological and ecotoxicological properties of these molecules have been evaluated at this stage in order to select the most promising molecules before proceeding to later evaluation stages in biological pilots. Table 1 shows that:

Vanillin shows an effectiveness from 0.5 ppm up to 20 ppm.

Pentaerythritol shows an efficiency in screening test in concentration ranges between 2 and 20 ppm with a significant decoupling factor because close to 20%.

Glycine betaine has optimal efficacy in the concentration range 2 to 8ppm.

Claims

1. A method for regulating the growth of bacterial biomass in an aqueous system comprising adding to the aqueous system, or contacting with the aqueous system, an effective amount of a decoupling agent selected from vanillin, pentaerythritol and a betaine of general formula (1):

(1) (R) ₃ N ⁺ - [CH¾] ri-CO 2 - in which:

2. Method according to claim 1, characterized in that in the formula (1) R is a methyl group and n = 1 and the product of formula (1) is the

trimethylglycine, N-trimethylglycine, glycine betaine or glycine.

3. Method according to claim 1 or 2, characterized in that the effective amount of the decoupling agent is between 0.005 and 5000 mg / l.

4. Method according to claim 3, characterized in that the effective amount of the decoupling agent is between 0.01 and 1000 mg / l.

5. Method according to claim 4, characterized in that the effective amount of the decoupling agent is between 0.01 and 300 mg / l.

6. Method according to claim 5, characterized in that the effective amount of the decoupling agent is between 0.05 mg / l to 100 mg / l.

7. Method according to claim 6, characterized in that the effective amount of the decoupling agent is between 0.1 mg / l to 10 mg / l.

8. The method of claim 7, characterized in that the effective amount of the decoupling agent is between 0.5 mg / l to 7.5 mg / l.

9. The method of claim 8, characterized in that the effective amount of the decoupling agent is between 1 mg / l to 5 mg / l.

10. Method according to claim 1, characterized in that the effective amount of the decoupling agent is between 0.1 mg to 1000 mg per gram of solids, expressed as solids, present in the sludge in the aqueous system.

1 1. Process according to claim 10, characterized in that the effective amount of the decoupling agent is from 1 mg to 500 mg per gram of solids present in the sludge in the aqueous system.

12. The method of claim 1 1, characterized in that the effective amount of the decoupling agent is between 5 mg to 100 mg per gram of solids present in the sludge in the aqueous system.

13. Method according to any one of the preceding claims, characterized in that the aqueous system is a wastewater treatment plant for the treatment of industrial effluents or municipal.